Journal Article

Evaluation of a saliva molecular point of care for the detection of SARS-CoV-2 in ambulatory care

Mercier-Delarue, Séverine, LeGoff, Jérôme, Kernéis, Solen, Néré, Marie Laure, Brazille, Patricia, Pavie, Juliette, Delaugerre, Constance, Gastli, Nabil, Alby, Marie-Laure, Leroy, Chrystel, Minier, Marine, Elie, Caroline, Quentin, Pierre, Gabassi, Audrey, Parfait, Béatrice, Choupeaux, Laure, Fourgeaud, Jacques, Tréluyer, Jean-Marc

2021

Overview

Rapid identification of SARS-CoV-2-infected individuals is a cornerstone for the control of virus spread. The sensitivity of SARS-CoV-2 RNA detection by RT-PCR is similar in saliva and nasopharyngeal swabs. Rapid molecular point-of-care tests in saliva could facilitate, broaden and speed up the diagnosis. We conducted a prospective study in two community COVID-19 screening centers to evaluate the performances of a CE-marked RT-LAMP assay (EasyCoV) designed for the detection of SARS-CoV2 RNA from fresh saliva samples, compared to nasopharyngeal RT-PCR, to saliva RT-PCR and to nasopharyngeal antigen testing. Overall, 117 of the 1718 participants (7%) tested positive with nasopharyngeal RT-PCR. Compared to nasopharyngeal RT-PCR, the sensitivity and specificity of the RT-LAMP assay in saliva were 34% and 97%, respectively. The Ct values of nasopharyngeal RT-PCR were significantly lower in the 40 true positive subjects with saliva RT-LAMP (Ct 25.9) than in the 48 false negative subjects with saliva RT-LAMP (Ct 28.4) ( p  = 0.028). Considering six alternate criteria for reference tests, including saliva RT-PCR and nasopharyngeal antigen, the sensitivity of saliva RT-LAMP ranged between 27 and 44%. The detection of SARS-CoV-2 in crude saliva samples with an RT-LAMP assay had a lower sensitivity than nasopharyngeal RT-PCR, saliva RT-PCR and nasopharyngeal antigen testing. Registration number : NCT04578509.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 631/326/596 / 631/326/596/4130 / 692/4017 / 692/699/255 / Adult / Ambulatory care / Ambulatory Care - methods / Antigens / COVID-19 / COVID-19 - diagnosis / COVID-19 - metabolism / COVID-19 Nucleic Acid Testing - methods / Diagnostic Tests, Routine / False Negative Reactions / False Positive Reactions / Female / Humanities and Social Sciences / Humans / Male / Middle Aged / Molecular Diagnostic Techniques / Molecular Medicine / multidisciplinary / Nasopharynx - virology / Nucleic Acid Amplification Techniques / Point-of-Care Systems / Point-of-Care Testing / Polymerase chain reaction / Prospective Studies / Real-Time Polymerase Chain Reaction / Reproducibility of Results / RNA, Viral - genetics / Saliva / Saliva - metabolism / SARS-CoV-2 / Science / Science (multidisciplinary) / Sensitivity and Specificity / Severe acute respiratory syndrome coronavirus 2